[PATCH v2] btrfs-progs: balance: deprecate old syntax

[Wang Yugui <wangyugui@e16-tech.com>]

deprecate btrfs blanace old syntax since new syntax is already introduced in
2012.

we will remove the old syntax completely in a few releases.

Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
---
changes since v1:
	fix typo(btrfs balance replace -> btrfs balance start)

 cmds/balance.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cmds/balance.c b/cmds/balance.c
index d1e66d42..3cb6334a 100644
--- a/cmds/balance.c
+++ b/cmds/balance.c
@@ -37,7 +37,7 @@
 
 static const char * const balance_cmd_group_usage[] = {
 	"btrfs balance <command> [options] <path>",
-	"btrfs balance <path>",
+	"btrfs balance <path>        deprecated by 'btrfs balance start'",
 	NULL
 };
 
@@ -882,6 +882,8 @@ static int cmd_balance(const struct cmd_struct *cmd, int argc, char **argv)
 		/* old 'btrfs filesystem balance <path>' syntax */
 		struct btrfs_ioctl_balance_args args;
 
+		warning("deprecated by 'btrfs balance start'");
+
 		memset(&args, 0, sizeof(args));
 		args.flags |= BTRFS_BALANCE_TYPE_MASK;
 
-- 
2.36.2